THE SCIENCE OF LIBIDO

There may be some times in your life when you feel as if you want to torch the sheets with your partner every night, and other times when the sexiest thing you can imagine is binge-watching baking shows. Or maybe you have sex every week or two and don't miss it when you don't.

Meanwhile, you hear about friends who are at it every day, and think, What's wrong with me? 

Well, we are here to tell you that the answer is, probably nothing.

Libido, a.k.a. sex drive or sexual desire, "is multifaceted and multidetermined, encompassing biological, medical, familial, cultural, relational, and individual factors," says sex therapist Laurie Mintz, Ph.D., an emeritus professor of psychology at the University of Florida and the author of Becoming Cliterate. With all those influences on whether you're motivated to have sex, it makes sense that your drive can ebb and flow, even throughout a week or month (indeed, for premenopausal women, monthly cycles affect libido).

And certainly, libido can vary through the broader phases of your life, says Susan S. Khalil, M.D., director of the Division of Sexual Health in the Raquel and Jaime Gilinski Department of Obstetrics, Gynecology, and Reproductive Science at Mount Sinai in New York City. When you're in your 20s, for example, curiosity about sexuality and pleasure tend to drive up desire. Libido can plummet in the months and years after you have a baby, then rise again when the baby stops keeping you up all night. During perimenopause, women experience a natural dip in sex hormones and may start to have issues with lubrication, which can affect how into it you are. One recent study found that women's desire tended to fluctuate more than men's throughout their lifetimes, but that people all had similar ups and downs on a weekly basis.

WHAT IS LIBIDO, EXACTLY?

Bear with us as we take you back to Sex 101: "Libido" is the term used to describe sexual desire or a desire for sexual activity, which may mean with a partner or the solo act of masturbation. It's not a medical term-it was coined by Sigmund Freud, and there isn't a universally accepted way to measure it.